1. Field of the Invention
The present invention relates to an image recording apparatus which includes a recording head for ejecting ink droplets onto a recording medium to record an image thereon, and is capable of recording an image on both of two opposite surfaces of a recording medium.
2. Description of Related Art
There is widely known an image recording apparatus of inkjet type having a recording head, from which ink droplets are ejected onto a recording medium while the recording medium is intermittently fed and passing an image recording position, so as to record an image thereon. There is known a kind of such an image recording apparatus that is capable of recording an image on both opposite surfaces of a recording medium. This image recording apparatus operates such that a recording medium is first supplied from a tray into a feed path by means of a pickup roller, and then fed along the feed path by a feeder roller to the recording position, where an image is recorded on a first one of two opposite surfaces of the recording medium. Thereafter, the recording medium is fed back onto the tray so as to be again supplied into the feed path by the pickup roller and fed to the image recording position by the feeder roller. At the image recording position, an image is again recorded on the recording medium, this time on a back side, i.e., a second surface, of the recording medium opposite to the first surface.
When an inkjet image recording apparatus records an image based on image data on a recording surface of a recording medium, it is known to reduce a time required to record the image across the entire recording surface, by a skip operation. It is noted that the no-image area corresponds to a non-recording area where no image exists in an image as actually formed or recorded on a recording surface based on the image data. The other part of the image data than the no-image area corresponds to an image area, and the other part on the recording surface than the non-recording area corresponds to a recording area. More specifically, the recording medium is fed continuously while a non-recording area on the recording medium is passing the image recording position. When an entirety of the non-recording area has passed the image recording position, that is, when a next leading end, in a direction of feeding of a recording medium, of a recording area on the recording surface reaches the image recording position, the feeding of the recording medium is switched from continuous to intermittent, so as to record an image across the recording area during the recording medium is intermittently fed.
The image recording apparatus capable of recording an image on both surfaces of a recording medium suffers from the following problem. That is, during recording of an image on a second surface of a recording medium, it can occur that the pickup roller is in contact with a first surface of the recording medium at the moment when feeding of the recording medium is switched from intermittent to continuous so as to skip a non-recording area on the second surface. When this occurs, the pickup roller may be unable to rotate following an abrupt acceleration of the recording medium, and slip on the recording medium. When the pickup roller slips in this way, the ink forming an image on the first surface may transfer or adhere to an outer circumferential surface of the pickup roller. Such transfer of the ink results in contamination of the outer circumferential surface of the pickup roller as well as possible degradation of the quality of the image having been recorded on the first surface.